Second Brain: Backend Engine

Goal: The primary objective of this project was building a "type-first" backend where the database models (MongoDB) and the API responses are strictly typed to prevent runtime errors and ensure data integrity.

Tech Stack:

• Runtime: Node.js
• Language: TypeScript
• Framework: Express.js
• Database: MongoDB with Mongoose
• Authentication: JWT / Bcrypt for password hashing
• Validation: Zod

Features Utilized TypeScript interfaces alongside Mongoose schemas to ensure end-to-end type safety from the database to the API response. Clean separation of concerns using a Controller-Service-Model pattern. Efficient handling of "Brain" content, including notes, tags, and categorical filtering. Implemented middleware for protected routes and password encryption.

The project follows a modular structure:

• Models: Defined MongoDB schemas with TypeScript types.
• Controllers: Logic for handling HTTP requests and status codes.
• Middleware: Centralized error handling and authentication checks.
• Routes: Cleanly mapped API endpoints.